Have you ever tried on a blouse or a shade of lipstick that makes your skin, eyes, and face come alive, only to try another one that’s almost exactly the same shade but makes you look tired, washed-out, and just generally off? The first one probably matched your skin’s surface tone and undertone perfectly, while the second shade may have a totally wrong undertone.

What’s that? You kinda understand, but don’t really know the difference between surface tone and undertone? Join the club. When it comes to fashion and beauty, there are few buzzwords as prevalent as “cool undertones” and “warm undertones” In fact, we’re always hearing that identifying which category we fall into is integral to our overall attractiveness, but finding out where we fall is still shrouded in confusion.

The first step in grasping the concept? Understanding that our skin’s surface tone is the color you’d describe yourself as having (ivory, light, medium, tan, dark, etc.) Your skin’s undertone is the color underneath the surface. You can have the same skin color as someone, but a different undertone, which are broken down like this:

One big misconcpeton: That pale girls can’t be warm-toned. In fact, many fair-skinned women have warm undertones (Nicole Kidman is one of them!) and dark-skinned women have cool tones (supermodel Alek Wek is a cool tone.)

So, how can you determine which category you fall into? Read on!

1. Check Your VeinsPush your sleeves up right now and look at the veins on the inside of your wrist. Are they blue or green? If they look more blue, you likely have cool undertones. If the veins look greenish, you’re warm. It’s worth noting, warm girls, that you’re veins aren’t actually green—they look it because you’re seeing them through yellow-toned skin (yellow + blue = green.)

2. The Good Old Jewelry Trick.
Think about whether you look better in silver or gold jewelry (Not which you like more, but which actually makes you look more radiant, glowing, and awake.) Typically, girls with cool undertones look better in silver and platinum metals, and warm-toned women look better in gold.

3. The Neutral Test.
Think about what neutral shades flatter you best. Does your skin, eyes, and face look better in bright white and black hues, or ivory, off-whites, and brown/tan shades? The former means you’re probably cool-toned, and the latter, warm.

4. Eye and Hair Color.
Your natural eye and hair colors can help figure out your coloring. Customarily, cool people have eyes that are blue, gray, or green and have blond, brown, or black hair with blue, silver, violet and ash undertones. Conversely, warm-toined women usually have brown, amber, or hazel eyes with strawberry blond, red, brown, or black hair. Their hair tends to have gold, red, orange, or yellow undertones.

5. The Sun’s Effects.
When you’re out in the sun, does your skin turn a golden-brown, or does it burn and turn pink first? If you fit into the former category, you’re warm-toned, while cool tones tend to burn (fair-skinned cool girls will simply burn, while medium-skinned cool-toned girls will burn then tan.)